Your best bet for our area and conditions will probably be the H-1000 or Retumbo. Tim went the RL-25 route and it will get your velocity , but it had some temp issues that we found were just not compatable with our weather.

The H-1000 is working very well with his RUM with the 180, 200, and 210gr bullets. Very consistant velocities and great groups.

No problem. The 88g H1000 load is mild, but accurate, you can probly start there. The 92g load is around max in my rifle, but still shot very well. The 95g Retumbo load is also around max in my rifle, I'd start around 90-91.

I will get with Tim on his loads today at work. As for the 25, it seems to be good for loads around the mid sized cases, but once you get into the UM size ones in our conditions down here, it don't take a lot of change to get the stuff to start jumping around.

Tim had an excellent load worked up with it and some 180's, and we were shooting it one morning with temps in the mid 70's. That afternoon, I took his rifle over to work on some hogs in one of their pastures, and bout locked the bolt up, with only about a 20 degree change. The case was noticably ruined.

RL-25 gave outstanding numbers 3263,3267,3261 with the 200AB, however this powder in this caliber is super temp sensitive down here next to sea level where we are. If you go with this powder then I recommend that you work the load up in the middle of August.

Stx- I have had real good luck using 180gr Swift Sciroccos and 99.gr of Retumbo this load will average 3400 out of my 28 inch Krieger barrel and shoots in the .5's @ 100yds. It also performs great on Elk!!

I just bought a 300 um . I have been reloading for my 7mag and 25-06 for several years with great results.I love those accubonds as they are excellent on muleys and elk. My question when talking temperature is How does temp and elevation effect the zero, say zero in in 90 degree heat in Texas and hunt in 16 degree weather in Colorado. I need to work up a load for white tails in old mexico as well as muleys and elk in Colorado..

About us

My family and I welcome you. I started LRH back in 2001 to provide a friendly place where like-minded individuals could share information and ideas to help take their long range shooting and hunting to the next level.